PENAMBAHAN CHITOSAN DAN PLASTICIZERGLYCERIN DALAM PEMBUATAN BIOPLASTIK BERBAHAN DASAR EKSTRAK PROTEIN AMPAS TAHU

Plastik sintetis merupakan plastik yang biasanya berbasis konvensional. Sumber bahan baku plastik sintetis merupakan energi yang tidak dapat diperbarui yaitu minyak bumi. Plastik sintetis memiliki sifat fisik yang fleksibel, ringan, kuat dan ekonomis. Plastik sintetis dapat menyebabkan permasalahan lingkungan yaitu sulitnya plastik sintetis yang terdegradasi oleh tanah. Sehingga dapat menurunkan kualitas tanah dan mikriorganisme. Upaya pencegahan permasalahan sampah plastik dapat dilakukan dengan pengembangan pembuatan plastik dari bahan polimer alami yang disebut bioplastik. Plastik biodegradableumumnya terbuat dari bahan polisakarida dan dapat terbuat dari sumber protein, salah satunya limbah tahu. Penelitian ini bertujuan untuk memanfaatkan limbah tahu yang diekstrak untuk diambil proteinnyasebagai bahan dasar pembuatan plastik biodegradable, serta untuk mengetahui sifat mekanik dan lama bioplastik protein ampas tahu terdegradasi oleh tanah. Pembuatan bioplastik membutuhakan bahan pemlastis dan bahan aditif untuk menghasilkan plastik yang fleksibel. Penelitian ini menggunakan penambahan plasticizerglycerin dengan variasi 30%,40%,50% dan bahan pengisi 20%. Penambahan chitosan sebanyak 5 ml. Hasil penelitian pembuatan protein ampas tahu menunjukkan bahwa kadar protein ampas tahu yang dihasilkan dari tahap diekstraksi sebesar 29.72%. Hasil pengujian kuat tarik bioplasik dari protein ampa tahu menggunakan alat UTM (Universal Testing Machine) yangberkisar antara 1.04-2.12 Mpa yang telah memenuhi standar bioplastik menurut Japan Industrial Standard (JIS). Sedangkan hasil pengujian daya serap air menggunakan metode swelling memiliki nilai tertinggi pada glycerin 50% sebesar 196% dalam kurun waktu 30 menit. Sedangkan daya serap paling baik terdapat pada variasi glycerin 30% sebesar 49.7%. Bioplastik berbahan dasar protein ampas tahu dapat terdegrdasi dengan sempurna dalam kisaran waktu 7-14 hari. Kata kunci: biodegradable plastik, biodegradasi, chitosan, glycerin, sifat mekanik. Synthetic plastics are plastics that are usually conventional based. The source of synthetic plastic raw material is non-renewable energy, namely petroleum. Synthetic plastics have physical properties that are flexible, lightweight, strong and economical. Synthetic plastics can cause environmental problems, namely the difficulty of synthetic plastics which are degraded by soil. So that it can reduce soil quality and microorganisms. Efforts to prevent the problem of plastic waste can be done by developing the manufacture of plastics from natural polymer materials called bioplastics. Biodegradable plastics are generally made of polysaccharides and can be made from protein sources, one of which is tofu waste. This study aims to utilize the extracted tofu waste for protein as a basic material for making biodegradable plastics, as well as to determine the mechanical properties and length of time for the tofu pulp protein to be degraded by the soil. The manufacture of bioplastics requires plasticizers and additives to produce flexible plastics. This study used the addition of glycerol plasticizer with a variation of 30%, 40%, 50% and 20% filler. The addition of 5 ml of chitosan. The results of the research on making tofu pulp protein showed that the protein content of tofu pulp from the extraction process was 29.72%. Bioplastic tensile strength value from tofu pulp ranges from 1.04-2.12 MPa which has met the bioplastic standards according to the Japan Industrial Standard (JIS). The highest water absorption capacity of bioplastics from tofu pulp protein was found in the glycerol 50% variation of 196% within 30 minutes. Meanwhile, the lowest absorption rate was found in the 30% glycerol variation of 49.7%. Bioplastics from tofu pulp protein can completely decompose in 7-14 days. Keywords: chitosan, degradation, glycerol, mechanical properties, plastic biodegradable.

Functional Characteristics Improvement of Edible Film through the Addition of Gambier and Bay Leaf Extract

Background: Composing functional edible film focused on local materials has been explored in this study. However, producing an edible film with strong capability as an antioxidant and antimicrobe has not been successful. The incorporation of one or more functional compounds, such as gambier extract and bay leaf extract into canna starch, should offer the solution. Objective: These compounds should work in synergy in order to improve the functional characteristics of edible film. Furthermore, the film should have mechanical characteristics which fulfille Japan Industrial Standard (JIS) (1975), i.e., it should belong to a strong category. Methods: This research studied the effects of gambier extract and bay leaf extract addition on edible film characteristics. A completely randomized design was used, and two factors were investigated, namely gambier extract (1.0, 2.0, and 3.0 percent, w/v) and bay leaf extract (0.0, 3.0, and 6.0 percent, w/v). Results: The parameters that were observed included mechanical (thickness, elongation percentage, water vapour transmission rate) as well as functional characteristics (antioxidant and antibacterial activity). The results showed that thickness, elongation percentage and water vapour transmission rate of the functional edible film were 0.18 - 0.27 mm, 7.33 - 9.00% and 30.43 - 46.07g.m-2.d-1, respectively, whereas antioxidant and antibacterial activity (value of inhibition diameter) were 23.24 - 40.58 mg.mL-1 and 1.33 - 1.83 mm, respectively. Conclusion: Edible film produced in this research had an antioxidant activity of strong category with a thickness that fulfilled JIS 1975 standard.

Spreadsheet-based method for predicting temperature dependence of fracture toughness in ductile-to-brittle temperature region

A spreadsheet-based simplified and direct toughness scaling method to predict the temperature dependence of fracture toughness Jc in the ductile-to-brittle transition temperature region is proposed. This method uses fracture toughness test data and the Ramberg–Osgood exponent and yield stress at the reference temperature, and yield stress at the temperature in interest to predict Jc. The physical basis of the simplified and direct toughness scaling method is the strong correlation between Jc and yield stress. The simplified and direct toughness scaling method was validated for Cr–Mo steel Japan Industrial Standard SCM440 and 0.55% carbon steel Japan Industrial Standard S55C by comparing the simplified and direct toughness scaling prediction results with the median results of an experiment performed at four temperatures ranging from −55°C to 100°C and at three temperatures ranging from −85°C to 20°C, respectively. The simplified and direct toughness scaling method can predict Jc from both low to high temperatures, and vice versa. Thus, 12 and 6 predictions were made for each material. The prediction discrepancy for these 18 cases ranged from −50.4% to +25.8% and the average absolute discrepancy was 22.1%. These results were acceptable considering the large scatter generally observed with Jc. In particular, in case of predicting Jc at temperatures higher than the lowest temperature of −55°C for SCM440, the simplified and direct toughness scaling method predicted Jc more realistically than the American Society for Testing and Materials E1921 master curve approach. Although the simplified and direct toughness scaling method requires additional tensile test data compared with the master curve approach, the acceptable prediction accuracy at high temperatures seems beneficial because the mass and time required for tensile tests are admissible.

Unicode Characters for Human Dentition

In this chapter, the authors report the minimal set of characters from the Unicode Standard that is sufficient for the notation of human dentition in Zsigmondy-Palmer style. For domestic reasons, the Japanese Ministry of International Trade and Industry expanded and revised the Japan Industrial Standard (JIS) character code set in 2004 (JIS X 0213). More than 11,000 characters that seemed to be necessary for denoting and exchanging information about personal names and toponyms were added to this revision, which also contained the characters needed for denoting human dentition (dental notation). The Unicode Standard has been adopted for these characters as part of the double-byte character standard, which enabled, mainly in eastern Asian countries, the retrieval of human dentition directly on paper or displays of computers running Unicode-compliant OS. These countries have been using the Zsigmondy-Palmer style of denoting dental records on paper forms for a long time. The authors describe the background and the application of the characters for human dentition to the exchange, storage and reuse of the history of dental diseases via e-mail and other means of electronic communication.

JSME Construction Standard for Superconducting Magnet of Fusion Facility “MATERIAL”

A construction standard for a large superconducting magnet for a fusion device has been established by Japan Society of Mechanical Engineers in Japan. This paper describes the outline of the part of “Material” and interprets some special features provided in the standard. The standard was composed based on Japan Industrial Standard. The materials used for the superconducting magnet structure was limited and divided into two groups. The first group is for the materials of which cryogenic strength are not limited and will be used under the design with the strength at room temperature. The other group composes of the materials of which cryogenic strength are provided. The former group includes forged austenitic stainless steel, Inconel 718, Ni and Ni alloy, Cu and Cu alloy and welding wires for these materials. The latter group holds cryogenic structural materials, such as JJ1 and 316LN steels. The design strength of these materials is given in a quadratic function from room temperature to cryogenic temperature when the material is used in an as-solution heat treated condition. The standard also equips the process to register the new materials. One shall be able to prepare the data set necessary to make registration, and submit to the JSME Code Committee to register the materials with the standard.